Kowshik Posted June 7, 2020 Posted June 7, 2020 Can any one plz clarify me that if speed for getting ETL is constant for each type of helicopter?? If not what all the the factors that will affect the speed of ETL?? Why there is range of speed 16-24 kts?
VampireNZ Posted June 7, 2020 Posted June 7, 2020 "Effective translational lift (ETL) occurs with the helicopter at about 16 to 24 knots, when the rotor—depending on size, blade area, and RPM of the rotor system—completely outruns the re circulation of old vortexes and begins to work in relatively undisturbed air." Obviously dependant on wind and a/c weight also. Lots of great sources of heli aerodynamics info on the net to learn all about the subject. https://fas.org/irp/doddir/army/fm3-04-203.pdf https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/helicopter_flying_handbook/ Chapter 2 http://www.aerostudents.com/courses/rotorcraft-mechanics-and-design/SeddonBasicHelicopterAerodynamics.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19790009640.pdf Vampire
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